Answer:
14.29%
Explanation:
We have Stock purchase price to be $8
We have the Put option purchase price to be $1.50
The Call option selling price is $0.75
From here we calculate the Total cash outflow as
8 + 1.5 - 0.75 = $8.75
The Total cash inflow after one year is put as $10
Therefore we have the risk free rate to be (10-8.75)/8.75 = 0.1429 = 14.29%